Rapid-scanning optical-resolution photoacoustic microscopy

快速扫描光学分辨率光声显微镜

• 批准号: 8057288
• 负责人: Jay Zhao
• 金额: $ 10万
• 依托单位: MICRO PHOTO ACOUSTICS, INC.
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-22 至 2012-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8057288
• 关键词: Adopted; Blood; Blood Flow Velocity; Blood Vessels; Blood capillaries; Blood flow; Body part; Caliber; Cardiovascular system; Chronic; Clinical; Confocal Microscopy; Detection; Distal; Fluorescence; Fluorescent Dyes; Frequencies; Gases; Gold; Hemoglobin; Homeostasis; Image; Imagery; Label; Laboratory Research; Lateral; Length; Life; Light; Lighting; Magnetic Resonance Imaging; Mainstreaming; Maps; Measurement; Measures; Metabolic; Microcirculation; Microscopy; Morphology; Mus; Noise; Nutrient; Operative Surgical Procedures; Optical Coherence Tomography; Optics; Organ; Organism; Oxygen; Pathologic; Perfusion; Permeability; Physiological; Positron-Emission Tomography; Preparation; Raman Spectrum Analysis; Relative (related person); Resolution; Scanning; Signal Transduction; Site; Speed; Structure; System; Techniques; Testing; Time; Tissues; Transillumination; Translations; Trees; Ultrasonic Transducer; Ultrasonics; Ultrasonography; Venous; absorption; capillary; density; design; imaging modality; in vivo; intravital microscopy; new technology; oxygen transport; two-dimensional; two-photon; vascular bed; wasting

DESCRIPTION (provided by applicant): We propose to develop rapid-scanning optical-resolution photoacoustic microscopy (OR-PAM), which is capable of label- free imaging of non-fluorescent optical absorbers. Optical absorption contrast is highly desirable for microvascular imaging and characterization because of the presence of endogenous strongly light-absorbing hemoglobin. The proposed imaging system can provide a 5-micron lateral resolution, a 15-micron axial resolution, a 1.2-mm imaging depth, and a 30-Hz B-scan frame rate. The following specific aims are proposed. Aim 1. System design and implementation: The proposed rapid-scanning OR-PAM is expected to outperform the current version in imaging speed by a factor of 10. Nearly diffraction-limited optical focusing is employed to achieve the lateral resolution. Absorption of the focused light produced photoacoustic waves due to thermoelastic expansion. Detection of the photoacoustic waves using a high-frequency focused ultrasonic transducer measures the internal light absorption distribution and hence provides a 3D mapping of the optical structure. OR-PAM is able to measure optical absorption with a relative sensitivity of 100%, the theoretical limit of any linear-effect imaging methods. Rapid scanning of the dual optical-ultrasonic foci is required to achieve a high imaging rate. Aim 2. Testing the imaging system in phantoms and living mice: The proposed OR-PAM system will be tested with phantoms and living mice to quantify the maximum imaging depth, spatial resolution, SNR, and the frame rate for B- scan imaging. PUBLIC HEALTH RELEVANCE: Microcirculation, the distal functional unit of the cardiovascular system, provides exchange sites for gases, nutrients, metabolic wastes, and thermal energy between the blood and the tissues. Pathologic microcirculation reflects the breakdown of homeostasis in organisms, which ultimately leads to tissue inviability. Therefore, the proposed in vivo microvascular imaging and characterization is of significant physiological, pathophysiological, and clinical importance.

描述（由申请人提供）：我们提出开发快速扫描光学分辨率光声显微镜（OR-PAM），其能够对非荧光光学吸收剂进行无标记成像。 由于内源性强吸光血红蛋白的存在，光学吸收对比度对于微血管成像和表征是高度期望的。 所提出的成像系统可以提供5微米的横向分辨率，15微米的轴向分辨率，1.2毫米的成像深度，和30赫兹的B扫描帧速率。 提出了以下具体目标。 目标1.系统设计和实施：拟议的快速扫描OR-PAM预计将在成像速度方面超过当前版本10倍。近衍射极限的光学聚焦被用来实现横向分辨率。聚焦光的吸收由于热弹性膨胀而产生光声波。使用高频聚焦超声换能器检测光声波测量内部光吸收分布，从而提供光学结构的3D映射。OR-PAM能够以100%的相对灵敏度测量光吸收，这是任何线性效应成像方法的理论极限。需要快速扫描的双光学超声焦点，以实现高成像速率。 目标二。 在体模和活体小鼠中测试成像系统：将使用体模和活体小鼠测试申报的OR-PAM系统，以量化B扫描成像的最大成像深度、空间分辨率、SNR和帧速率。 公共卫生关系：微循环是心血管系统的远端功能单位，为血液和组织之间的气体、营养物质、代谢废物和热能提供交换场所。 病理性微循环反映了生物体内稳态的破坏，最终导致组织失活。 因此，所提出的体内微血管成像和表征具有重要的生理学、病理生理学和临床重要性。